Browse Topic: Foot
A significant portion of the global population about 13.6% of the world's population faces challenges due to upper limb disabilities caused by accidents, genetics, health issues or aging. These people struggle with everyday mobility tasks and often need help. Hence, the research is focused on creating special vehicle control systems to help them. This study gathers knowledge from various science and technology fields to develop foot-operated steering systems letting those with upper limb differences control vehicles with their feet. The research explores various technologies like modified steering, brain-controlled vehicles, foot-operated steering, steer-by-wire and Ackermann steering. Most of these systems are custom-made for people with upper limb differences. Ensuring safety, security, malfunction prevention, precise steering, user-friendliness and affordability is a significant challenge that demands advanced technology. Furthermore, there is a requirement to develop this system to meet modern demands while sustaining cost-effectiveness. In the pursuit of addressing the mobility challenges encountered by individuals with upper limb differences the research undertook a thorough assessment of various steering mechanisms such as Disk Steering, Joystick Steering, Push Button Steering…etc. The proposal introduces a foot-operated press button system to replace hand-operated steering wheels. Drivers can steer with their feet by engaging a press button on the steering pad. It connects directly to a controller which interfaces with a motor connected to a pinion pin. This motor moves the wheels precisely responding to the driver's interaction with the foot-operated press button and it is seamlessly connecting with steer-by-wire technology ensuring precise and responsive steering. whether they are using custom made vehicles or regular vehicles equipped with our proposed mechanism.
The purpose of this document is to provide the user with the procedures needed to properly assemble and disassemble the 50th percentile male Hybrid III dummy, certify its components and verify its mass and dimensions. Also within this manual are guidelines for handling accelerometers, repairing flesh and setting joints.
The Insurance Institute of Highway Safety (IIHS) introduced driver side small overlap test in 2012 and added the passenger side small overlap test in 2018 to the top safety pick plus ratings requirement. The injury of a passenger’s outboard right foot in the passenger-side small overlap rigid barrier (PSORB) test is of more concern compared to the driver’s outboard left foot in the driver-side small overlap rigid barrier (DSORB) test. The reason is, the passenger’s right foot is positioned just above the carpet on the toe pan, and is closer to the barrier during the PSORB impact event, unlike the driver’s outboard left foot in DSORB, which rests on a stiff foot rest. So it is often necessary to develop countermeasures to protect the passenger from lower leg injuries. This paper describes a time efficient method to model the PSORB occupant sled model using finite element modeling and it also demonstrates the model’s application in the process of countermeasure development for the protection of a passenger from lower leg injuries. Finite element (FE) models of the Hybrid-III dummy, passenger airbag, knee airbag, seat belt system and other critical vehicle components and assemblies were modeled as required and integrated in the sled model. A detailed finite element model of the carpet assembly was also modeled. The paper also explains a quick and simple scaling method used to generate the Ls-Dyna material properties of the different grades of carpet foam, from its respective compression test data. The overall results of the base model and the countermeasure model were validated and confirmed with their respective internal small overlap rigid barrier tests. The proposed method of modeling the sled model has shown to be effective with respect to computational time and robust in predicting the passenger’s lower tibia axial force response for a given intrusion rate of the toe pan.
This document describes the 2-D computer-aided design (CAD) template for the HPM-1 H-point machine or HPD available from SAE. The elements of the HPD include the curve shapes, datum points and lines, and calibration references. The intended purpose for this information is to provide a master CAD reference for design and benchmarking. The content and format of the data files that are available are also described.
This document describes the 3D computer-aided design (CAD) parts and file formats for the HPM-1 H-point machine available from SAE. The intended purpose for this information is to provide a master CAD reference for design and benchmarking.
Robots have replicated much of the human sensory experience on Mars. Cameras have given us sight; robotic hands, arms, and feet have supplied touch; and chemical and mineral sensors have let us taste and smell on Mars. Hearing is the last of the five senses yet to be exercised on the Red Planet.
Occupant dynamics during passenger vehicle underride has not been extensively evaluated. The present study examined the occupant data from IIHS rear underride crash tests. A total of 35 crash tests were evaluated. The tests were classified as full-width (n = 9), 50% overlap (n = 11), and 30% overlap (n = 15). A 2010 Chevrolet Malibu impacted the rear underride guard of a stationary trailer at 35 mph. Several occupant kinematics and dynamics data including head accelerations, head injury criteria, neck shear and axial forces, neck moments, neck indices, chest acceleration, chest displacement, chest viscous criterion, sternum deflection rate, and left/right femur forces/impulses, knee displacements, tibia axial forces, upper/lower tibia moments, upper/lower tibia indices, and foot accelerations were measured. The vehicle accelerations, delta-Vs, and occupant compartment intrusions were also evaluated. The results indicated that the head and neck injury parameters were positively correlated with driver A-pillar rearward intrusion. The 30% overlap crashes showed significantly higher intrusion and head and neck injury values than the 50% and full-width crashes. No strong relationship between head and neck injury parameters and vehicle delta-V or peak acceleration was observed. None of the chest injury criteria exceeded the chest IARV tolerances in the crash tests examined. No relationship between chest injury parameters and vehicle delta-V, acceleration or driver A-pillar rearward intrusion was observed. No strong relationship was observed between left/right leg injury parameters and vehicle delta-V, acceleration or driver A-pillar intrusion. Only for two crash tests, the “left upper tibia A-P moment”, “left upper tibia resultant moment” and “left upper tibia index” exceeded the IARV tolerances. This study suggested that in underride crashes there is a higher chance of head/neck injuries than other body regions. Also, in addition to delta-V, other parameters such as percent overlap and occupant compartment intrusion should be taken into consideration when analyzing the biomechanics of underride.
During Operation Iraqi Freedom and Operation Enduring Freedom, improvised explosive devices were used strategically and with increasing frequency. To effectively design countermeasures for this environment, the Department of Defense identified the need for an under-body blast-specific Warrior Injury Assessment Manikin (WIAMan). To help with this design, information on Warfighter injuries in mounted under-body blast attacks was obtained from the Joint Trauma Analysis and Prevention of Injury in Combat program through their Request for Information interface. The events selected were evaluated by Department of the Army personnel to confirm they were representative of the loading environment expected for the WIAMan. A military case review was conducted for all AIS 2+ fractures with supporting radiology. In Warfighters whose injuries were reviewed, 79% had a foot, ankle or leg AIS 2+ fracture. Distal tibia, distal fibula, and calcaneus fractures were the most prevalent. The most common injury mechanisms were bending with probable vehicle contact (leg) and compression (foot). The most severe injuries sustained by Warfighters were to the pelvis, lumbar spine, and thoracic spine. These injuries were attributed to a compressive load from the seat pan that directly loaded the pelvis or created flexion in the lumbar spine. Rare types of injuries included severe abdominal organ injury, severe brain injury, and cervical spine injury. These typically occurred in conjunction with other fractures. Mitigating the frequently observed skeletal injuries using the WIAMan would have substantial long-term benefits for Warfighters.
SAE International defines six levels of autonomous driving system, four of which include a change of control from the system to the driver in certain conditions. When vehicle control changes from the system to a human driver, a safe transition time is necessary. The present study focuses on level 3 automation, in which the system controls driving in ordinary conditions, but the human driver is expected to intervene in emergency situations. The aim of this study was to investigate the relationship between driver posture and transition time. Driver posture included four components: backrest angle, seat position, foot position, and arm position. These were adjusted to investigate a total of 30 posture patterns. In addition, the situation in which the driver was not watching the road, but instead using a tablet computer was investigated. The driver’s braking and steering reaction times were measured for a highway-driving scenario in which a truck dropped cargo in front of the vehicle. Acoustic and optical warnings were presented to the driver when the autonomous driving system was disengaging. The results showed that the driver’s foot position most strongly affected braking reaction time. The driver resting their chin on their hands most strongly affected steering reaction time. This research clarified the effect of relaxed driver posture on reaction time and, thus, transition time.
At the collision moment, a driver’s lower extremity will be in different foot position, which leads to the different posture of the lower extremity with various muscle activations. These will affect the driver’s injury during collision, so it is necessary to investigate further. A simulated collision scene was constructed, and 20 participants (10 male and 10 female) were recruited for the test in a driving simulator. The braking posture and muscle activation of eight major muscles of driver’s lower extremity (both legs) were measured. The muscle activations in different postures were then analyzed. At the collision moment, the right leg was possible to be on the brake (male, 40%; female, 45%), in the air (male, 27.5%; female, 37.5%) or even on the accelerator (male, 25%; female, 12.5%). The left leg was on the floor all along. Muscle activation of gastrocnemius, vastus medialis and vastus lateralis of right legs of male drivers in brake pedal region were significantly larger compared to the other positions, and that of soleus and hamstrings were significantly greater compared to air region. Gluteus maximus showed small muscle activation all along (<10%). Right leg showed larger muscle activation than left leg in the air and brake pedal region for most muscles of both genders (except for gluteus maximus). The right and left legs were in different postures at the collision moment, which affects the muscle activation. Differences were also found between muscles and genders. Therefore, muscle activation should be precisely measured, and the influence of these factors should be considered in the future injury analysis of lower extremity.
Due to the accidents of the motor vehicles and the osteoporosis, many people enface a lot of troubles and sometimes necessities for replacement of their knee joints. Practically, mechanical properties and surface characteristics of Total Knee Replacement (TKR) are very important parameters for improving the performance response in human. The meniscus is a small element and an essential part of the TKR. The knee meniscus has special feature allows the easy dynamic loading and motion of leg and foot with high accuracy and good balance. Therefore design and analysis of the geometrical shape for the meniscus replacement is worthy to be studied. In this paper, a proposed design using a computer software package has been presented. 3D simulation analyses of a variety of meniscus thickness and different materials under different loads are investigated. The compression stresses and surfaces deformations are determined numerically through the Finite Element Analysis (FEA) technique. A developed polymeric material reinforced by Carbon Nanotube particles (CNTs) is discussed. The thickness of meniscus for both the tibia-direction (Ht) and the femur-direction (Hf) has insignificant effect on the compression stresses and surface deformation. While, the developed material of 50 wt.% UHMWPE, 48wt.% HDPE and 2wt.% CNTs showed the lowest deformation on the meniscus surface. In addition, a proposed prototype of a polymeric material for the design of the meniscus has been manufactured by a CNC machine. The dimension trueness and accuracy of fabricated prototype as metrological characteristics for knee meniscus replacement are also evaluated. Moreover, uncertainty estimation for dimensional measurement has been studied and confirmed the confidence degree of the fabrication accuracy for the proposed prototype.
Nowadays, studying the human body response in a seated position has attracted a lot of attention as environmental vibrations are transferred to the human body through floor and seat. This research has constructed a multi-body biodynamic human model with 17 degrees of freedom (DOF), including the backrest support and the interaction between feet and ground. Three types of human biodynamic models are taken into consideration: the first model doesn't include the interaction between the feet and floor, the second considers the feet and floor interaction by using a high stiffness spring, the third one includes the interaction by using a soft spring. Based on the whole vehicle model, the excitation to human body through feet and back can be obtained by ride simulation. The simulation results indicate that the interaction between feet and ground exerts non-negligible effect upon the performance of the whole body vibration by comparing the three cases.
Transport Canada, through its ecoTECHNOLOGY for Vehicles program, retained the services of the National Research Council Canada to undertake a test program to examine the operational and human factors considerations concerning the removal of the side mirrors on a Class 8 tractor equipped with a 53 foot dry van semi-trailer. Full scale aerodynamic testing was performed in a 2 m by 3 m wind tunnel on a system component basis to quantify the possible fuel savings associated with the removal of the side mirrors. The mirrors on a Volvo VN780 tractor were removed and replaced with a prototype camera-based indirect vision system consisting of four cameras mounted in the front fender location; two cameras on either side of the vehicle. Four monitors mounted in the vehicle - two mounted on the right A-pillar and two mounted on the left A-pillar - provided indirect vision information to the vehicle operator. Four commercial drivers were asked to perform a series of tests simulating typical driving scenarios on a closed course test track. The tests included an object identification test, a blind spot comparison test, a coupling and uncoupling test, a quasi-static lane change test, a dynamic lane change test and an evasive manoeuvres test. The tests were performed both with the mirrors and with the camera-based indirect vision system. The results of the study provide an analysis of driver performance while using the mirrors in comparison to driver performance while using the camera-based indirect vision system. Driver acceptance of the camera-based indirect vision system was also analyzed through the use of questionnaires.
A soft, wearable device that mimics the muscles, tendons, and ligaments of the lower leg could aid in the rehabilitation of patients with foot-ankle disorders such as drop foot, said Yong-Lae Park, an assistant professor of robotics at Carnegie Mellon University, Pittsburgh, PA.
This SAE Standard is intended to improve operator efficiency and convenience by providing guidelines for the uniformity of location and direction of motion of operator controls used on industrial wheeled equipment. The controls covered are those centrally located at the operator's normal position.
Improvised Explosive Devices (IEDs) and Anti-Tank (AT) mines are a significant threat for military vehicles and their occupants. These explosive devices are designed for the destruction and damage of armored and other vehicles, by using them in battle fields on routes of army vehicles. The blast event results in effects like shockwave, fragments, fire, gases, blast overpressure as well as the vertical impulse load. A blast event affects occupants inside the vehicle in the form of various types of injuries (lower leg, spinal, chest, head etc) and trauma. The Lower leg is the foremost injured body region in a blast event. The term lower leg is used to designate the tibia, fibula and the foot/ankle complex in this paper. Detonations occurring under a vehicle produce high velocity floorboard flutter/deformation and transmit axial loads to lower leg and create injuries. In order to mitigate lower leg injury, countermeasures like seat mounted footrests, surrogate floors; energy-absorbing aluminum honeycomb footpads and specially-developed foam / rubber carpets are being widely used. Based on the proven energy absorption technique, TATA Motors has developed a new cost effective polymer-based footpad in which dual mode energy absorption methods are being introduced. These energy absorption methods are: 1 Energy absorption through horizontal-vertical air slots 2 Energy absorption through crushing of thin polymer walls arranged in particular geometry. This footpad is highly cost effective when compared to commercially available footpads of similar shape, size & performance. This paper describes the development of cost effective footpad which is reducing lower leg injuries during blast events.
The research question investigated in this study is what are the key attributes of foot and ankle injury in the between-rail frontal crash? For the foot and ankle, what was the type of interior surface contacted and the type of resulting trauma? The method was to study with in-depth case reviews of NASS-CDS cases where a driver suffered an AIS=2 foot or ankle injury in between-rail crashes. Cases were limited to belted occupants in vehicles equipped with air bags. The reviews concentrated on coded and non-coded data, identifying especially those factors contributing to the injuries of the driver's foot/ankle. This study examines real-world crash data between the years 1997-2009 with a focus on frontal crashes involving 1997 and later model year vehicles. The raw data count for between-rail crashes was 732, corresponding to 227,305 weighted, tow-away crashes. A previous study suggested that the frequency of between-rail crashes (where the direct damage is between the 2 longitudinal rails) is about 6.1% of all frontal crashes. Further, it was suggested that the between-rail crash has a higher risk of AIS ≥ 2+ fatality than any other crash type studied. For between-rail crashes, approximately 15% of the AIS ≥ 2+ fatality injuries were to the foot or ankle. The distribution of AIS = 2 injuries is presented by anatomical structure for the foot and ankle. The significance of the results is that the between-rail frontal crash inflicts high levels of disability on the driver.
The design and analysis plays a major role for determining the root cause for the problem. Once the problem and its root cause were well defined, the solution for addressing the problem would be made clear. The engine excitation frequency and the chassis natural frequency were coming closer and it leads chassis to resonate. The resonance increases vibration levels at the Tractor footrest which was reducing comfort level of the operator. The vibration reduction methodologies like stiffening the structure, isolating the source from excitation and dampening techniques were studied to reduce vibration levels at footrest. The benchmarking evaluation was done with selected tractor models qualitatively to assess the difference in vibration level perception for customers. The test methodology and data acquisition methodology was formulated and used for better analysis and discussions. In this paper, the author demonstrated the systematic approach to reduce tractor footrest vibrations by 20%-25% through concept design, virtual analysis and experimental validation.
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